People are increasingly connected via social networks. People opt into or voluntarily join various online social networks to share thoughts, common interests and media. When people are on their computers, they can generally see when people within their social networks are also connected on-line.
However, when people leave their homes and travel to various locations, they may not realize that people within their social networks are nearby. Some people may desire to know when friends, family or people within their social network are within or near a current location, even if they do not see them or know that they were coming to or near the current location.